Railway car impact retarder



Nov. 26, 1957` D. w. LowE 2,814,364 RAILWAY CAR IMPAeT RETARDER Filed Dec. 51. 1956 mnnllm Y I y n) INVENTOR. w h/an/f nitecl States Patent nice 2,814,364 Patented Nov. 26, 1957 RAILWAY CAR IMPACT RETARDER David W. Lowe, Baltimore, Md. ApplicatonDecember 31, 1956, Serial No. 631,949 4 Claims. (Cl. 18S- 148) The present invention relates to an improved railway car impact retarder, and in particular to a uid operated device which utilizes the conventional air brake mechanism already carried on the car and is a modification of my Patent No. 2,725,121.

In shifting cars and making up trains and for taking cars in and out of trains there are many times that the cars are freed from the rest of the train and allowed to roll free toward another car to be stopped when the other car is contacted. No control is had over the brakes on that particular car while it is rolling free, except by the emergency hand brake. As the amount of speed the car must have at the time it is released from the train to make its journey can not be very well determined, the car is nearly always given the maximum speed to carry it the distance, consequently, the free-rolling cars many times may contact the stationary cars at a rate of l() miles an hour which is damaging to the cars and to the contents they may be carrying, and many times no one is on the released car to operate the hand brake.

Releasing the cars and allowing them to roll free for most of their run saves considerable time in making up trains, or releasing Icars along the routes upon sidings.

The primary object of the invention is to provide means for operating the present car brake which are normally operated by air, of a free moving car to apply the brakes just prior to contact with another car for reducing the speed of the free moving car.

Another object of the invention is to provide a mechanism that may be easy and inexpensive to attach to the present day railway car and its braking mechanism.

A further object of the invention is to provide a device that may be applied to the present day railway car without altering in any way the present air or hand operation of the brake.

While several objects of the invention have been set forth, other objects including its uses and advantages may become apparent to one skilled in the art as the nature of the invention is more fully disclosed which, consists of its novel construction, combination and arrangement of its several parts as shown in the drawings and described in the following detail description; in the drawings:

Figure 1 is a schematic plan view of the bottom of a railway car showing the relative position and attachment of the impact retarder in respect to the air brake and linkage to the brakes.

Figure 2 is an enlarged sectional view of one of the essential elements of the impact retarder.

Figure 3 is an enlarged fragmentary sectional View of a releasable Huid valve which may be set at predetermined pressures.

In referring to the drawings, like numerals are used to point out like and similar parts throughout the several views.

In Figure l there is schematically shown a bottom of a conventional railway car having a conventional cylinder 12, a rod 14 which has one end connected with a piston (not shown) movable along the inside of the cylinder. The opposite end of the rod 14 is connected to a link 16 by the pin 16. The link 16 is hingedly connected to a cross-bar 18 which in turn is connected with rods 20 and 22 leading to the brakes for the wheels (not shown) located at each end of the car. At 24 there is indicated an air inlet pipe to the cylinder 12, the air being supplied from any well-known supply source.

Normally the cross-bar 18 stops at the link 16, but in this case it is continued to a point where it can be conveniently connected to the retarding device.

The retarding device comprises a hydraulic cylinder 26. Operating Within the cylinder 26 is a pair of pistons 28 and 30. Connected to the piston 28 is one end of a piston rod 32, and connected to the piston 30 is one end of a piston rod 34. Each of the pistons has a bleeder opening 28 and 30 respectively. There is provided in piston 30 a pressure relief valve 36. This valve is provided with a movable sealing member 31 acting in only one way. The movable member is loaded with a compression spring 38 the compression of which may be varied to regulate the pressure at which the movable member 31 will operate to open the valve. The valve supporting casing is in two pieces each piece 36' and 36" being screwed in from opposite sides of the piston head whereby the pressure on the spring 38 may be varied for predetermining the amount of pressure for opening the valve.

The opposite end of the piston bar 32 is connected to one end of a gear rack member 40 having teeth 40. The opposite end of the rack is connected to one end of an operating bar 42. The outer end 42 of the operating bar is hinged at a point 44 adjacent the carin order that the operating bar may be folded up out of operating position when a car has been uncoupled and standing alone.

The piston rod 34 connected with the piston 30, has its opposite end connected to a link member 46 which in turn is connected with the cross-bar 18 by the pin 46.

Extending parallel with the operating rod 42 is a second operating rod 48. This rod 48 has one end connected to one end of a gear rack 50, similar to gear rack 40. The teeth 50 on the gear rack 50 and the teeth 40 on the gear rack 40 face each other and are connected with a toothed gear wheel 52. The gear wheel 52 is rotatably retained within a suitable bracket 54 for holding the gear in a ixed location between the racks. The gear racks engage opposite sides of the gear wheel 52. This arrangement moves the gear racks in opposite directions when the gear 52 is rotated, or if the gear 52 is rotated in one direction by the movement of one of the racks, either rack 40 or rack 50 will move, the other rack in the opposite direction. The outer end 48' of the operating rod 48 is also hinged as described for the parts 42 of the rod 42 (the hinge not being shown). On the outer ends of the rods 42 and 48' there are contact plates 60 and 62 for contacting the adjacent end of the car toward which the free-rolling car is moving.

When either operating rod 42 or 48 is moved inwardly the rod 32 connected with piston 28 moves in the direction of the arrow shown in Figure 2.

The hydraulic cylinder is kept full of suitable luid through an opening shown at 64, to which a supply pipe may be connected. A conduit 66 is provided to convey the iluid from one end of the cylinder to the other as the pistons are moved to release either pressure, or the vacuum created behind the moving pistons.

The cars are usually provided with automatic couplings as shown at 63 and 69, for pivotally connecting the cars to each other.

In operation, when the free moving car gets within a short distance or a predetermined distance of the car toward which it is moving, either the contact plate 60 or 62 comes in contact with that car to operate the impact retarder. As the free-moving car moves closer toward the car to which it is moving, the rod 48 or 42 is depressed, moving the piston 28 through the cylinder 26 in the direction of the arrow, shown in Figure 2. As the piston 28 is moved to the position shown by the dotted lines 28", the piston 30 is moved toward the position shown by the dotted lines 30". When the pistons are moved, the conduit 66, being connected with the cylinder adjacent its ends at 66', and 66 relieves any pressures or vacuums that would be built up between the outer end of the piston and the end of the cylinder.

When the piston 30 reaches a position such as indicated by the dotted lines 30, the brakes are applied and piston 30 stops its travel toward its respective end of the cylinder. However, the movement of the car may continue to push the piston 28 further into the cylinder. To take care of this additional movement when the pressure between the pistons has increased to a predetermined amount, the movable member 31 of the valve will be lifted from its seat and the uid will pass through the valve to the back of the piston 30 and through the conduit 66 to the rear of piston 28.

When the forward motion of the piston 28 is stopped, Huid will leak through the bleeder openings 28 and 30 relieving the pressure between the piston. Piston 30 will return to its normal off braking position. When the folded end 42 or 48' of the operating rods 42 and 48 have been folded up and the force on the rods 42 or 48 has been released by folding up their respective ends 42 or 48 as previously described, the piston 28 will be returned to its normal position as indicated in full lines in Figure 2.

For moving the piston 28 to its normal resting place there is provided a compass-like member having a pair of hinged members 70 and 72. One end of each of the members is hingedly connected as shown at 75. The other end of one of the members 70 is hingedly attached to a stationary plate 73 by the pin 74, which is fixed to the bottom of the car. The opposite end of the other member 72 is hingedly connected to one end of the rack 40 by the pin 76. Extending approximately one-third the length of the member 70 from the pin 75 is an aperture 70', and extending approximately one-half of the distance between the end of the member 72 is an aperture 72'. Between apertures 70' and 72' is a coiled tension spring 76 which is extended when the rack moves toward the cylinder 26. The action of the spring 76 moves the rack back to its normal resting place and acts to extend the rods 42 and 48 to their normal distance beyond the outer end of the car so that the extensions 42 and 48' are in position to contact the car toward which the free moving car is moving, as has been described hereinbefore.

While one form of the invention has been illustrated and described in detail, it is not intended as a limitation and it is to be understood that certain changes of construction, combination and arrangement of its several parts may be made by those skilled in the art without patentable variations from the disclosure set forth which will fall within the scope of the appended claims herein and the scope of the invention is best defined in the appended claims.

I claim:

1. In a wheel supported railway car having a braking system including means for engaging said wheels and means for automatically operating the said brakes comprising, in combination, a secondary brake operating means for automatically operating the said brakes when the car is in free rolling movement and in a predetermined distance of an adjacent railway car, said second operating means comprising a hydraulic cylinder being iilled from end to end with a suitable liquid, a compression producing piston adjacent one end of the cylinder and a movable pressure receiving piston carried adjacent the opposite end of the cylinder adapted to be moved by the operation of the compression producing piston, an operating means for the said compression producing piston comprising arms extending outwardly from and beyond each end of the car adapted to be slidably carried thereon in the general direction of the movement ofthe car, one end of each of the said arms being connected to a piston rod, the said piston rod extending through one end of the cylinder having its opposite end connected with the pressure producing piston, means associated with the two slidable arms for operating either arm in the opposite direction when the other arm is being moved relative to the car, resilient means for normally maintaining the slidable arms in their extended position, the pressure receiving piston having one end of a piston rod connected thereto and extending outwardly from the piston rod through the opposite end of the cylinder, the opposite end of the piston rod being connected to the braking mechanism, whereby the movement of the pressure receiving piston will actuate the said brakes when moved by the operation of the compression piston through the movement of either of the slidable arm members.

2. In a braking system as set forth in claim l in which a valving and by-passing means is associated with the cylinder and pistons set for a predetermined pressure for allowing the uid to pass from one portion to another portion of the cylinder when the pressure between the pistons has reached said predetermined pressure.

3. In a braking system as set forth in claim 1 in which a pressure relief valve is located to receive the pressure of the liquid between the pistons for admitting the liquid to the opposite side of the piston when a predetermined pressure has been built up between the pistons and means for conveying the liquid passing through the valve to the area between the piston and the end of the cylinder.

4. In a braking system as set forth in claim l in which the ends of a cylinder are connected by conduit for relieving the pressure and vacuum in the areas between the pistons and the cylinder ends.

No references cited. 

